This basic and clinical research will determine cellular enzyme activities and metabolite levels in each specific microdissected uterine cell type throughout rat implantation sites and in the epithelium and stroma of luteal phase individual human endometrial biopsies. Current microanalytical biochemical technques employing enzymatic cycling allow amplification and measurement of enzyme activities and metabolite levels from nanogram or less freeze dried samples of microdissected tissue of a single cell type. The three objectives of this research are: to determine the effect of estrogen with and without progesterone on control of energy metabolism in each specific uterine cell type. The enzyme activity dose response relationship to various doses of estradiol-17 beta with and without progesterone will be determined in ovariectomized rats. Initial enzyme activities to be studied are hexokinase, phosphofructokinase and lactate dehydrogenase from the glycolytic pathway, citrate synthase from the Krebs citric acid cycle and beta-hydroxyacyl-CoA dehydrogenase involved in fatty acid metabolism. To determine the pattern of energy metabolism in each cell type throughout rat implantation sites and the blastocyst. To apply microbiochemical techniques to the study of individual human endometrial biopsies. The importance of applying these microtechniques to individual patients lies in the possibility of discovering specific biochemical differences between individual patients. This work is designed to determine the effect of sex steroids and implantation on the energy metabolism of each specific uterine cell type. This work is the basis for research to determine the cellular biochemical abnormalities of implantation which may be associated with habitual abortions, stillbirths and environmental or drug-induced abnormalities of fetal growth and development.